/*
 * File    : Handler.java
 * Created : 19-Jan-2004
 * By      : parg
 * 
 * Azureus - a Java Bittorrent client
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details ( see the LICENSE file ).
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.gudy.azureus2.core3.util.protocol.dht;

/**
 * @author parg
 *
 */

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;

import org.gudy.azureus2.core3.util.Base32;
import org.gudy.azureus2.core3.util.ByteFormatter;
import org.gudy.azureus2.core3.util.Debug;

public class Handler extends URLStreamHandler {
    public URLConnection openConnection(URL u) {
        // format is dht://<hash>[.dht]/[params]
        // treat as magnet magnet:?xt=urn:btih:<hash32>/params

        URL magnet_url;

        try {
            String str = u.toString();

            str = str.substring(6);

            int param_pos = str.indexOf('/');

            String hash = param_pos == -1 ? str : str.substring(0, param_pos);

            hash = hash.trim();

            int dot_pos = hash.indexOf('.');

            if (dot_pos != -1) {

                hash = hash.substring(0, dot_pos).trim();
            }

            if (hash.length() == 40) {

                hash = Base32.encode(ByteFormatter.decodeString(hash));
            }

            magnet_url = new URL("magnet:?xt=urn:btih:" + hash + "/" + (param_pos == -1 ? "" : str.substring(param_pos + 1)));

        } catch (Throwable e) {

            Debug.out("Failed to transform dht url '" + u + "'", e);

            return (null);
        }

        // System.out.println( "Transformed " + u + " -> " + magnet_url );

        try {
            return (magnet_url.openConnection());

        } catch (MalformedURLException e) {

            Debug.printStackTrace(e);

            return (null);

        } catch (IOException e) {

            Debug.printStackTrace(e);

            return (null);
        }
    }

}
